Field of the Invention
The present invention relates to radiation imaging apparatuses, radiation imaging systems, and a method for controlling the radiation imaging apparatus.
Description of the Related Art
Radiation imaging apparatuses including a matrix substrate including pixel arrays having a combination of switches, such as thin-film transistors (TFTs) or the like, and converting elements, such as photoelectrical converting elements or the like, have been put into practical use as radiation imaging apparatuses for use in medical imaging diagnosis and non-destructive tests using radiation, such as X-rays, etc.
In recent years, it has been studied to increase the functions of radiation imaging apparatuses. An example is to include a function for monitoring irradiation of radiation. This function enables, for example, detection of timing at which the irradiation of radiation from a radiation source is started, detection of timing at which the irradiation of radiation is to be stopped, and detection of the dose of radiation or the integrated dose of radiation.
Japanese Patent Application Laid-Open No. 2012-15913 discusses a radiation imaging apparatus including image capturing pixels for acquisition of radiation images and detecting pixels for detection of radiation. Further, Japanese Patent Application Laid-Open No. 2012-15913 discusses an arrangement in which signals for detecting radiation are read via switch elements connected to the detecting pixels. Further, Japanese Patent Application Laid-Open No. 2012-15913 discusses an arrangement in which a driving voltage is switched as appropriate between a conductive voltage and a non-conductive voltage in order that the conductive state of the switch elements is switched at the time of reading the signals of pixels for detection.
However, in the radiation imaging apparatus discussed in Japanese Patent Application Laid-Open No. 2012-15913, the electrical potential of the signal lines may change at the time of switching the driving voltage due to parasitic elements (parasitic capacitances) between control lines and the signal lines connected to the switch elements as a result of a change in voltage of the control lines. The change in electrical potential of the signal lines sometimes leads to inadequate accuracy of detection of irradiation of radiation.